Room-temperature wafer bonding of LiNbO 3 and SiO 2 using a modified surface activated bonding method

In this paper, we report room-temperature bonding of LiNbO 3 (LN) and SiO 2 /Si for the realization of a LN on insulator (LNOI)/Si hybrid wafer. We investigate the applicability of a modified surface activated bonding (SAB) method for the direct bonding of LN and a thermally grown SiO 2 layer. The modified SAB method using ion beam bombardment demonstrates the room-temperature wafer bonding of LN and SiO 2 . The bonded wafer was successfully cut into 0.5 × 0.5 mm 2 dies without interfacial debonding owing to the applied stress during dicing. In addition, the surface energy of the bonded wafer was estimated to be approximately 1.8 J/m 2 using the crack opening method. These results indicate that a strong bond strength can be achieved, which may be sufficient for device applications.